公开(公告)号：US3847831A

公开(公告)日：1974-11-12

申请号：US7643870

申请日：1970-09-29

Applicant: STAMICARBON

Inventor： SLOT H ,  GEUS J

IPC: B01J23/28 ,  B01J23/31 ,  B01J23/34 ,  B01J23/88 ,  B01J23/881 ,  B01J23/887 ,  B01J11/22

CPC classification number: C07C253/26 ,  B01J23/28 ,  B01J23/31 ,  B01J23/34 ,  B01J23/88 ,  B01J23/881 ,  B01J23/8876 ,  Y02P20/52 ,  C07C255/08

Abstract: 1. A PROCESS FOR THE PREPARATION OF A CATALYST SYSTEM CONTAINING OXIDES OF BISMUTH, MOLYBDENUM AND IRON WHICH CONSISTS ESSENTIALLY IN CARRYING OUT THE STEPS OF: (A) FORMING AN AQUEOUS ACID SOLUTION CONTAINING IONS OF BISMUTH, AND IONS OF IRON IN AN ATOMIC RATIO NO GREATER THAN 0.4:1 RELATIVE TO SAID BISMUTH IONS, AND AN AQUEOUS ALKALINE SOLUTION, INJECTING ONE OF SAID SOLUTIONS INTO THE OTHER WHILE MAINTAINING THE PH OF THE RESULTING AQUEOUS SOLUTION AT A VIRTUALLY CONSTANT VALUE OF AT LEAST ABOUT 7 WHEREBY A PRECIPITATE OF COMPOUNDS OF SAID IONS IS FORMED, AND SEPARATING SAID PRECIPITATE FROM SAID RESULTING AQUEOUS SOLUTION; (B) FORMING A SUSPENSION OF SAID PRECIPITATE IN AN AQUEOUS MEDIUM, ADJUSTING THE PH OF SAID SUSPENSION TO A VALUE OF BETWEEN ABOUT 2.5 AND 7, AND WHILE HEATING AND AGITATING SAID SUSPENSION, AND MAINTAINING THE PH OF SAID SUSPENSION AT A VALUE OF GREATER THAN ABOUT 2.5, INTRODUCING AN AQUEOUS SOLUTION OF AMMONIUM MOLYBDATE INTO SAID SUSPENSION IN AN AMOUNT IN EXCESS OF A MOLYBDENUM TO BISMUTH ATOMIC RATIO OF ABOUT 1:1 BY AN AMOUNT OF MOLYBDENUM STOICHIOMETRICALLY EQUIVALENT TO THE QUANTITY OF IRON PRECIPITATED IN STEP (A), AND AT A RATE NO GREATER THAN 0.1 GRAM MOLE OF MOO4 PER LITER OF SUSPENSION PER HOUR, THEREAFTER HEATING SAID SUSPENSION AT OR NEAR THE BOILING TEMPERATURE FOR A PERIOD OF AT LEAST 6 HOURS WHEREBY SUBSTANTIALLY ALL OF SAID MOLYBDENUM IS TAKEN UP BY SAID PRECIPITATE.